This invention relates to an apparatus for mounting cables. Particularly, the invention is directed towards such mounting apparatus as used in a residential, industrial or commercial application for the purposes of supporting objects from or securing objects to a wall, ceiling or other surface by a cable.
It is frequently desired to mount objects from walls or ceilings. One way of accomplishing this type of mounting is to attach one or more cables, guy wires or other support lines to the object. One end of the cable must be firmly attached to a surface such as a wall or ceiling. An eyebolt or the like is often used with a loop formed in the end of the cable, wire or line. This combination can be unsightly and insecure since with just one point of threaded connection into the structure, the eyebolt is susceptible to coming loose, for example, by being rocked back and forth and thus loosened from the supporting structure.
Frequently, the desired location of the object necessitates less than optimal connection with the wall or ceiling. Furthermore, architectural design elements featuring wall sections that depart from vertical, or ceiling sections that depart from horizontal also necessitate less than optimal connection with the wall or ceiling. The cable support should permit the cable to extend away from the support surface at any desired angle to accommodate variability in the location of the mounted object and to accommodate mounting surfaces that depart from vertical or horizontal. The difficulty of mounting to a wall or ceiling can be exacerbated by the weight of the object and a desire to minimize shear across and abrasion of the cable. Correct angular positioning of the run of cable from mounting surface to supported object can avoid contacting the cable with, and bending it around a part of either its anchor or other objects.
Most rigging and cabling techniques rely on the crimping of ferrules onto the cable as a means to form a loop or attaching a standard fitting. The crimping process is usually done with specialized, usually hydraulic equipment xe2x80x9cat the factory.xe2x80x9d Special hand crimping tools are available but not commonly so. They are awkward to use on a ladder particularly when an The installer must push the tool""s handles together at the same time as pulling a cable into tension.
There exists some non-traditional type fittings that do allow some on-site adjustability. Some incorporate a collet and sleeve compression arrangement, some have barbs or teeth that grip the cable. These non-traditional fittings are not readily available, are costly and are often viewed as inadequately field-proven.
Preferably, a surface mounted anchor should be as visually pleasing as possible. However, the objectives discussed above are particularly difficult to realize in a cable anchor that is not a visually intrusive addition to the architectural environment in which it is used. Furthermore, architectural features may constrain the point at which a cable anchor can be secured. The anchor may need to be fastened into subsurface uprights or beams. Here again, maximum adjustability of the angle at which the cable runs without sacrificing the security of the mounting or the appearance of the anchor is much to be desired.
In accordance with the present invention, a cable anchor is provided that is readily adjusted for the extension of a cable (or wire, cord or other line) in any of numerous directions away from the anchor. One or more of the anchors and attached cables can be the principal support for the object or they can be secondary support acting in concert with a primary support such as a bracket, shelf or frame type of support. For example, the cable anchor of the invention can, with its attached cable, be the primary means of hanging an object from a ceiling or overhang, and on the other hand, the anchor and its cable may be used to keep a television from sliding off of supporting shelf in, say, a hospital room.
The cable connection is pivotal about two axes to accommodate the various directions in which the cable can be extended. Unlike the eyebolt, which has only the single point of attachment into a mounting surface, the anchor of this invention provides two attachment points by two bolts securing it stably to the mounting surface. Thus, it provides better load distribution and significantly increased capability for much higher load bearing at the mounting surface. Because it has a surface bolted flat against the mounting surface and bolted there by the two bolts, it is not susceptible to being rocked back and forth such that the bolts will be loosened.
The present invention provides an apparatus for mounting objects that affords flexibility and ease of use and placement by allowing full adjustability of the angle at which a cable extends from an anchor at the same time being connected stably to a support surface and having an aesthetically pleasing, unobtrusive appearance. The flexibility and ease of use is not limited to flexibility of placement and adjustability of cable angle however. The anchor of the present invention differs from the traditional cable and rigging methodologies mentioned in that both the desired length of the cable and its ability to be installed in tension is easily managed at the installation site. The cable anchor according to this invention facilitates ease of installation by requiring only that a small hex key be used to apply a tightening force via a set screw to a point along the cable length. The ease of tightening the cable to the surface mounted anchor offers unique installation advantages. In an actual installation, this means that one hand can be free to apply tension and support to a cable or to adjust the vertical height of the object being supported by the cable. In other words, one person, using one hand, has the freedom to pull the cable and apply either tension, vertical height adjustment or both, related to positioning the object being supported, while the other hand can simultaneously turn the hex key, and with normal force applied to only one of three set screws, secure the cable in place anywhere along its length. When it is executed on a ladder, this is much safer from a balance and stability point of view. Using a manual crimping tool on the other hand, one person ordinarily could not accomplish this. It would be extremely difficult or impossible to hold the ferrule in place, pull tension on the cable and push the manual crimp tool handles together all at the same time.
As used herein, xe2x80x9ccablexe2x80x9d is meant to encompass a multistrand wire cable, coated or uncoated, a guy wire, a single strand wire or a cord or flexible elongate member of any kind suitable to support an object. The cable anchor of the present invention provides for flush mounting on a wall or ceiling or even a subsurface member. Additionally, a cover screens the mechanical connecting parts of the mounting apparatus from view and provides an unobtrusive, attractive outer appearance.
The apparatus of a preferred embodiment of the invention comprises a pivotal U-shaped mounting base or bracket that supports a pivotal shaft. One end of the mounting cable connects to the shaft. Preferably, it passes through a cable passage in the shaft. In the preferred embodiment, the cable passes through a passage bored along a diameter of the shaft. It then passes through and around an anchor-block. The cable is threaded through one and then back through another of two substantially parallel anchor-block passages, then through another passage through the shaft. Once the cable has been properly tensioned with an appropriate tool, set-screws mounted in the anchor-block securely hold the cable in place. The anchor-block is pulled tightly against the shaft.
The use of set screws as a means of securing aircraft type cable is known and accepted. It is frequently used in race cars for example, as a means of securing control cables for accelerator linkage and brake cabling. It is believed not to have previously used in the manner of this invention, however.
In addition, what is believed a particularly unique feature in the present invention is the use of the three set screws and a loop back feature. Collectively, the set screws when properly tightened, provide redundancy and bring the point of attachment up to or beyond the break strength of the cable itself. Typically crimped ferrules are rated to 70% of the maximum cable strength. The cable anchor loop back feature of this invention, in and of itself, contributes to the holding power of the anchor block. The cable, looping back on itself, creates friction interference, engaging an anchor block through which it is threaded. The security is enhanced by the third set screw in the anchor block which is deliberately positioned after the loop.
The pivotal shaft provides one degree of freedom within which the mounting cable can rotate, i.e. in a plane substantially perpendicular to the rotational axis of the pivotal shaft. In addition, the base or bracket is rotatable about a hole that accepts a first one of the mounting bolts or screws. An arcuate slot centered on the hole receives the further bolt or screw to fix the base or bracket in fixed angular position on the support surface. The combination of the slot and mounting bolt provides an additional degree of rotational freedom allowing the pivotal shaft to be aligned substantially perpendicular to the run of the cable to the mounted object, so that the cable supports the object without any force being directed against the cable""s side, but rather, along its length. By preventing forces directed laterally to the cable, shear on the cable and abrasion of the cable is eliminated or minimized. Such weakening as results from flexure is eliminated or substantially reduced.
The outer cover for the cable anchor of the invention preferably is slotted to allow the cable to pass through it in any of a number of directions without interference and has internal fingers that mesh with mounting holes on a portion of the mounting base. This engagement securely holds the cover and also ensures that the slot is appropriately aligned with the point of affixation of the mounting cable to the underlying shaft. The cover slot permits passage of the cable at any angle through a 90xc2x0 range of angles afforded by the pivotal mounting of the underlying shaft to which the cable is secured. A further 90xc2x0 of angular variability is afforded to the cable run by the cover being adapted to be turned 180xc2x0 and mounted. By virtue of this, its slot can extend in either of two opposite directions to allow passage of the cable in the desired direction.